United Nations experts on torture and human rights express concern over the fate of a Guantánamo detainee sent to Algeria last week.

Algerian Djamel Ameziane, a 42-year-old ethnic Berber, has been approved for release but wants to go to Canada, or another country, rather than the nation he fled in 1992. His lawyers have chosen Canada because he lived there for five years, and filed a failed application for political asylum. From Canada he went to Afghanistan, where he was captured in the U.S. invasion.

Two top United Nations officials said Tuesday they were concerned about the welfare of a Guantánamo captive whom the U.S. repatriated to Algeria last week after a decade in the detention center in southeast Cuba.

In a joint statement issued from Geneva, the U.N. Special Rapporteurs on torture, and on human rights and counterterrorism, Juan E. Méndez and Ben Emmerson, respectively, warned that former detainee Djamel Ameziane, 46, may be at risk after his involuntary transfer from Guantánamo Bay to Algeria.

“We are deeply concerned that the life of Mr. Ameziane could be in danger in Algeria,” they said.

The United States has said it was assured by Algerian authorities that Ameziane and another detainee, Belkacem Bensayah, 51, would be treated humanely. They were returned Wednesday to what attorneys for other released Guantánamo prisoners described as up to 12 days of questioning incommunicado.

Ameziane’s attorney, Wells Dixon, said Tuesday morning that his family had yet to hear from him.

The rapporteurs made no mention of the Bensayah case although his attorney had, like lawyers for Ameziane, also sought resettlement in a Western nation rather than return to the north African nation each man fled in the 1990s.

In Washington, Ian Moss of the State Department’s office for Guantánamo closure said Tuesday that the U.S. “is satisfied that the Algerian government will continue to abide by lawful procedures and uphold its humane treatment obligations under domestic and international law in managing the return of Mr. Ameziane and Mr. Bensayah.”

Moss added that the United States had “received no credible or substantiated information to suggest that any of the 14 detainees previously transferred from Guantánamo to Algeria have been mistreated.”

In Geneva, however, the U.N. officials said: “Diplomatic assurances are unreliable and ineffective in protecting against torture and ill-treatment, and states should not resort to them. We have often seen diplomatic assurances used by governments to circumvent the absolute prohibition of torture as established in the U.N. Convention against Torture and Other Forms of Cruel, Inhuman or Degrading Treatment or Punishment.”

Separately, a State Department official said no other country had agreed to take in those two Algerians, making resettlement not a feasible option. The official spoke on condition of anonymity because that person was not authorized to discuss alternatives to last week’s transfer.